Sony has become the latest company to bring its digital book service to iOS with the new Reader app for iPhone, iPad, and iPod touch. Available to download for free from the App Store, the app offers access to all the books you have stored in your Reader library, and allows you to sync your bookmarks between other Reader devices.

TED’s new ebook series and ebook app highlights the concern that ebook purchases lock readers into specific platforms.

The TED organization, which sponsors a range of conferences and talks on cutting edge topics recently launched an ebook series known as TED Books. Like the non-profit’s other initiatives, TED Books are “designed to spread great ideas.” Sticking to that ideal, the organization is making the ebooks, which will be released every two weeks, available across a range of ebook platforms including the new TED Books app for iOS devices.

The move highlights one of the challenges about ebooks – the choice of merchant and platform. That’s a particular concern when it comes to Apple’s iBookstore because purchases can only be read on an iOS device.

A group of Chinese authors have reportedly filed a lawsuit against Apple in Beijing claiming that the Cupertino company is infringing copyright with books sold through its iBookstore. The Chinese financial magazine Caixin reports that nine authors from the China Written Works Copyright Society (CWWCS) are involved in the suit, which is hoping to secure 11.9 million yuan ($1.9 million) in compensation.

Well, that didn’t last long: just a few hours after being yanked from the iOS App Store for failing to comply with Apple’s revised in-app purchasing rules forbidding direct links to outside, web-based e-stores, Google Books has been re-instated, sans the offending link.

Nicely done, Apple. Looks like no one can afford to play hardball with you on this, not even Google or Amazon.

Apple has just seemingly banned its first big name app for not playing along with Apple’s revised In-App Purchase rules, as Google’s official Google Books app, which contained a prominent web link to an outside e-store, has disappeared from the App Store. If it has happened to Google, will Amazon’s Kindle app be the next app to disappear?